In the United States, about 2 million new homes and many thousands of new commercial and industrial buildings are constructed every year. During the earliest stages of construction, temporary power is provided at the building site for electric power tools. As construction progresses, a power panel and associated branch circuit breakers are installed along with electric circuits that will ultimately provide power throughout the structure. Typically, however, no power is provided to these circuits until the entire electrical installation has been completed, and all circuits are in place. This allows for the correction of any defects that may be identified prior to the formal inspection. This preliminary inspection requires that the structure be energized or “heated up” with temporary electric power. Many techniques have been used to provide this temporary electric power for checking the electrical circuits in the structure.
One commonly used technique for checking the electrical circuits of a structure involves stripping the insulation from two short pieces of copper wire. The pieces of wire are then forced into two power receptacles of a socket that is provided on the power panel for connection to an electric power meter. Specifically, in this method, the female plug is removed from a 240 volt extension cord and the insulation of the cord is stripped off. The stripped ends of the cord are then connected and taped to the short copper wires extending outward from the meter socket jaws. With this connection completed, the extension cord is plugged into a 240 volt receptacle. As a result, power is provided to the structure's electrical system. Clearly, this technique and other similar techniques produce significant fire hazards and safety risks. For instance, the bare wires used in making the temporary power connection can arc and start a fire. Further, due to improper installation, a ground fault within the electrical system may not be detected and could result in a fire before detection occurs. Moreover, if a neutral wire is not properly grounded, the voltage applied thereto may float between the two phases of electricity and lead to over or under voltage in the circuit. This presents the possibility of a 240 volt electrical shock, with a consequent failure of tools and/or equipment. Further, the use of bare conductors to connect temporary power to a structure presents a danger of shocking workers in the area. In fact, shocks are possible whether the bare conductors are connected as intended, or whether they are inadvertently disconnected from the panel.
A second technique for checking the electrical circuits of a structure involves stripping the insulation off of two hot wires of an extension cord, and feeding the two exposed wires into the load side of a breaker. Then the entire electrical system is back-fed from the extension cord. This method includes the same attendant fire and electrocution hazards as discussed above. In addition to those hazards, if the temporary connection is left in place and the electric meter is installed by the local utility, then the utility grid could be back-fed, resulting in risks to utility workers.
Another technique involves the connection of temporary power to either an air conditioning disconnect or a 240 volt ac dryer or oven outlet. This technique, however, is not preferred because it could also provide a back feed to the entire system causing risk of electric shock. Further, this technique allows the disconnect or outlet to be energized while exposed.
In light of the above, it is an object of the present invention to provide a device and method that provides for inspection of an electrical system which significantly reduces the threat of electrical shock or fire. Another object of the invention is to provide a device and method for inspecting an electrical system which avoids the use of stripped wiring. Still another object of the invention is to provide a device and method for preventing or reducing the threat of fires when a circuit having a fault is inspected. Still another object of the invention is to provide a device and method for diagnostic testing of an electrical system which utilizes a Ground Fault Circuit Interrupter (GFCI) upstream of the system. Yet another object of the present invention is to provide a device and method for inspecting electrical systems which is easy to implement, simple to perform, and cost effective.